The present invention relates to a composition that may in particular be used as solvent composition in phytosanitary formulations, the method for producing the composition and phytosanitary formulations containing the same.
A number of chemicals are used as solvents in industry, for example for preparing chemical products and materials, for formulating chemical compounds, or for treating surfaces. For example, solvents are used for the formulation of plant protection active substances in particular in the form of Emulsifiable Concentrates (“EC”) meant to be diluted with water by the farm operator prior to being applied over a field.
Thus, the phytosanitary formulations must allow for easy dilution by weight by the farm operator in order to obtain a product in which the phytosanitary product is properly dispersed, for example in the form of a solution, emulsion, suspension, or suspo emulsion. Phytosanitary formulations thus make it possible to transport a phytosanitary product in a relatively concentrated form, and allows for easy packaging and/or easy handling for the end user. Various different types of phytosanitary formulations can be used for different phytosanitary products. These include for example Emulsifiable Concentrates (“EC”), concentrated emulsions (Emulsion in water “EW”), micro emulsions (“ME”), Wettable Powders (“WP”) and granules that are dispersible in water (Water Dispersible Granules, “WDG”). Formulations that may possibly be used depend upon the physical form of the phytosanitary product (for example solid or liquid), and its physical-chemical properties in the presence of other compounds such as water or solvents.
After being diluted by weight by the farm operator, for example by mixing with water, the phytosanitary product may be present in various physical forms: solution, solid particle dispersion, dispersion of droplets of the product, droplets of solvent in which the product is dissolved, etc. Phytosanitary formulations generally comprise compounds that provide the ability to obtain these physical forms. They may be, for example, surfactants, solvents, mineral support media, and/or dispersants. Quite often these compounds do not have an active nature, but are meant rather to be of an intermediary assisting nature in the formulation. It is therefore quite often desirable to limit the quantity thereof in order to reduce the costs and/or any potential harm to the environment. Phytosanitary formulations may in particular be in liquid or solid form.
For practical reasons (for example, for reasons related to ease of handling and/or transportation), it may be preferable at times to use phytosanitary formulations in solid form, and to use formulations in liquid form at other times.
For the purpose of preparing phytosanitary formulations of solid phytosanitary active substances, it is a known technique to dissolve the product in a solvent. The phytosanitary formulation thus comprises a solution of the product in the solvent. The formulation may be in solid form, for example as a wettable powder (WP) where the adsorbed solution is an inorganic carrier material, for example kaolin and/or silica. The formulation may alternatively be in liquid form, for example in the form of an emulsifiable concentrate (EC) having a single clear liquid phase comprising the solvent and the product in solution, which is capable of forming an emulsion by addition of water, with no stirring or with very little stirring. It may also be in the form of a concentrated emulsion (EW), cloudy in appearance, of which the water dispersed phase comprises the solvent and the product in solution in the solvent. It may also be in the form of a clear micro emulsion (ME), of which the water dispersed phase comprises the solvent and the product in solution in the solvent.
Certain solid phytosanitary active substances are often difficult to formulate. For example, tebuconazole is a highly effective fungicide whose use is widespread, in particular for the cultivation of soybeans. For some phytosanitary active substances, it is difficult to produce concentrated formulations, which may be easily diluted by the farm operator, that are stable, and present no substantial disadvantages (real or perceived) in terms of safety, toxicity and/or eco toxicity. In case of some active substances, it is difficult to produce them at relatively high concentrations, with sufficient stability. In particular, it is necessary to prevent the appearance of crystals especially at low temperatures and/or during dilution thereof and/or during storage at high temperature of the diluted composition. The crystals may cause negative effects, in particular by clogging the filters of devices used to spread the diluted composition, clogging the spraying devices, reducing the overall activity of the formulation, creating unnecessary problems of waste stream channels for removing the crystals and/or resulting in poor distribution of the active ingredient in the cultivation site.
The use of solvent systems based on N-methylpyrrolidone (NMP) as a co-solvent is already known. This co-solvent provides the ability to improve the solubilisation of a large number of active substances, and to prevent the formation of crystals, however, it is found to be toxic to the reproductive system (reprotoxic) and as such as being potentially hazardous, in particular for the operators and users who handle it. There is a need for alternative solvent systems, presenting in particular:                a high degree of modularity, that is to say, an ability to be used for a large number of active substances,        potential for solubilisation of significant quantities of active substances,        high compatibility of several active substances in order to overcome the resistance phenomena,        absence of crystallisation, even in demanding conditions, and/or        a safety, toxicology and/or eco toxicology profile perceived to be favourable.        
The agrochemical industry is looking for new solvent compositions having properties that are satisfactory for phytosanitary application, like for example, good solvent power for phytosanitary active substances as well as low miscibility with water. In addition, the cost of the solvent compositions should be modest, and they should have a favourable toxicology and/or eco toxicology profile, in particular low toxicity and/or low hazard potential, low volatility (low VOC—volatile organic compounds) and high degree of biodegradability.
Some compounds that are known such as Polarclean® or N-methylpyrrolidone (NMP) or Dimethyl Sulfoxide (DMSO) are good solvents for phytosanitary active substances. However, their immiscibility with water is yet to be improved, especially when the intended application is the preparation of emulsifiable concentrates.
Also known are compounds such as dimethylocta decamides or alkyl dimethylamides (ADMA), which are immiscible with water but do not have a suitable solvent power that is satisfactory for a wide range of active ingredients.
Hence the inherent problem in this domain pertains to providing a compound that has both a good solvent power as well as satisfactory water miscibility properties.